Oxygen analyzers are used extensively in industrial process control. When used in such control applications, these analyzers typically incorporate three major components--a zirconium dioxide sensor which produces a voltage output signal representative of oxygen concentration within the gas sample being analyzed, a heater to elevate the temperature of the sensor to a required operating temperature, and a heater control circuit to maintain the sensor temperature independent of environment. It has been found that the use of a typical zirconium oxide sensor for industrial process control has a number of inherent disadvantages. For example, typically the use of such a sensor requires the utilization of many associated parts, clamps, seals and fasteners making assembly and/or replacement a difficult task. In addition, it has been found that tight gas seals are difficult to maintain. Also, alignment of the components comprising the assembly is difficult to achieve and maintain. The zirconium dioxide sensor must be located in the gas stream and the heater and thermocouple must be aligned with the sensing tip. It has been further found that exposure of the heater element to the corrosive gas stream reduces heater life. And lastly, complex heater control circuitry is required because of the low mass of the heater. Temperature control is critical to prevent deviations of the sensor output.
Because of the foregoing, it has become desirable to develop a simplified system for analyzing the oxygen content of a gas utilized in an industrial process. Such a simplified system should minimize the criticalness of controlling heater temperature within the sensor.